1. Technical Field
The present invention relates to a printer (the electronic device) that switches between and uses plural communication units appropriately to the operating mode, and relates particularly to a printer that can appropriately change the operating mode according to use of the printer and improve power conservation.
The invention also relates to a printer that changes and operates in an operating mode appropriate to the communication conditions, and relates particularly to a printer that can easily and appropriately return from the power conservation mode to the normal operating mode.
2. Related Art
Printers and other electronic devices typically execute processes based on communication from a host device that is connected to a network. Because such electronic devices therefore do not perform their main operation when not communicating with the host device, they often enter a power conservation mode that conserves energy by cutting off the power supply to part of the device.
JP-A-2011-68038 and JP-A-2013-161122 describe technology related to changing the operating mode. JP-A-2011-68038 teaches a communication control device that saves a job to be processed and maintains the power conservation mode without cancelling the power conservation mode even when a job to be processed by an information processing device is received. JP-A-2013-161122 teaches a data processing device for more appropriately managing information related to control of the power mode, and describes analyzing received packets to discard the packets or generate a response packet.
JP-A-2014-6929 describes technology that is related to a power conservation mode as described above, and determines whether or not to resume the normal operating mode when a device receives packets while in a power conservation state.
However, the devices described in JP-A-2011-68038 and JP-A-2013-161122 do not have two communication units separately provided for the normal operating mode and power conservation mode, and these disclosures are silent about the conditions for changing the operating mode in a device that has two communication units.
Some devices with two such communication units are also designed to enter the power conservation mode when communication with the host device is cut off. However, the host device may send requests to such devices at random times, and cannot enter the power conservation mode even if a request is not received for a long time in an operating environment where a quick response is needed because of the amount of time required to re-establish a communication link from the power conservation mode.
Such devices can be designed to uniformly resume the normal operating mode if TCP packets are received while in the power conservation mode, but this type of control may require a long time to change the operating mode depending on the operating conditions of the device, and because the power conservation mode is cancelled, is undesirable from the perspectives of power conservation and response speed.
JP-A-2014-6929 also requires a complicated process to determine whether or not to return to the normal operating mode.
Furthermore, because the condition for going to the power conservation mode is not limited to interruption of communication and differs according to the printer, the normal operating mode is preferably resumed under conditions appropriate to the conditions for entering the power conservation mode.